Al-Kindi... was the first Muslim to delve into philosophy and all its parts, including logic, naturalism, mathematics, and theology, in addition to his proficiency in Arab sciences and his proficiency in literature, including grammar and poetry. He knew medicine, the astrology and its rulings, and various types of industries and knowledge that were rarely found in one person. The various sciences are the foundation on which civilizations are built. Philosophy is the crown that unites the edges of this civilization. Religion is the spirit that breathes life into it. Al-Kindi was able to speak the language of Arabism from the point of view of its religion, which is Islam, and from the point of view of the civilizational sciences that raise the status of nations. He was familiar with these sciences and summarized them well. He wrote them in a sound Arabic language, and created for them terms that were understandable, current in use, and acceptable to taste. Thus, the Arabic language, with its words and structures, proved that it is the language of civilization, and Arab nationalism was able to stand firmly on its feet in the battle of nationalities, and to win this battle for several centuries.